DESCRIPTION: This study investigates the costs and benefits of giving parents more choice over schooling. It analyzes two of the most popular methods of expanding choice: charter schools and open enrollment programs. The first part of the study evaluates Massachusetts charter schools, comparing the achievement of students who attend them with students who applied to them but were randomly rejected by admissions lotteries. The general question is whether charter schools offer environments better suited to certain students but currently unavailable in the public schools. Specific questions include whether charter school students perform better on standardized tests, are more likely to graduate from high school on time, or are more likely to enroll in college. Because it uses a random control group, this study is likely to provide the first reliable evidence on such questions. The second part of the study analyzes the financial and governance structures of the twenty-nine open enrollment and charter school programs in the U.S. The overall question is how these programs should be structured to provide maximum net social benefit. Specific questions include how much revenue a district that receives a student under open enrollment should get, and whether this revenue should come from the district that loses the student. Because the study rigorously analyzes how parents and schools react to the incentives given by different program structures, its evidence is likely to help predict the effects of proposed programs and formulate better ones. This is in contrast to studies that assume that all reforms associated with the same name are the same (typical of the literature on past education reforms); these often produce conflicting evidence and little conceptual understanding of how the reforms affect behavior.